JP2914823B2 - Depth representation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for expressing depth in a computer game device.

[0002]

2. Description of the Related Art Usually, a computer game is displayed on a flat screen. For this reason, the displayed image is also planar. For example, when a person passes each other, there is no priority of the persons to be displayed and the images are displayed on a random basis. This sometimes resulted in a display that seemed strange.

In a general computer game device, a display object is managed by being divided into a sprite (foreground) and a background (background). And when displaying these, it is designed so that the priority display of the sprite and the background can be designated.

[0004]

However, when the sprite passes through the middle of the three-dimensional structure, the background is displayed preferentially or the sprite is preferentially displayed, so that only one of them is displayed preferentially. , Or can only take one of these methods.

[0005] For this reason, it is difficult to make a subtle expression such that a person is hidden in a part of the building. As a result, it is difficult to express a powerful image lacking in realism.

SUMMARY OF THE INVENTION It is an object of the present invention to clarify the context of an object, to create a screen having a depth, and to obtain sprite-to-sprite and sprite-to-background display methods.

[0007]

The conventional problem is that the object is managed two-dimensionally because it is a plane coordinate. That didn't matter much when moving left and right on the screen. However, in games that act three-dimensionally (left, right, up, down) as in recent years, unnaturalness is conspicuous, and the screen has become less powerful.

Therefore, in the present invention, a display object is managed in three-dimensional coordinates regardless of two-dimensional and three-dimensional, and a display priority is set in accordance with a depth to perform display. In a typical home computer game device, V as shown in FIG.
In many cases, images are displayed by a RAM.

In this example, a display object is divided into a foreground (sprite) and a background (background) to manage the VRAM. In this case, the display method of the display target differs depending on the sprite versus sprite and the sprite versus background.

First, the display of sprites versus sprites will be described. In FIG. 2, the person in front appears to float in the air. This is because, after displaying the back person (A), the front person (B) is displayed.

When the coordinate management relating to the depth is not performed, it is impossible to determine which one should be displayed preferentially by the program, and since the sprite display is performed at random, the expression as shown in FIG. 2 appears. is there.

Therefore, in the present invention, a reference point is provided, and the depth and the distance from the reference point are managed. The most common is to use three-dimensional coordinates as shown in FIG.
Expressed in coordinates. Even if the screen display is a plane as shown in FIG. 2,
The program performs three-dimensional management as shown in FIG. That is, the coordinates of the front person can be expressed as (X1, Y1, Z1), and the coordinates of the rear person can be expressed as (X2, Y2, Z2).

Each record of the SAT for managing a sprite represents one sprite, and has a configuration as shown in FIG. There is no representation of the coordinate value in the Z direction.
Therefore, the images are sorted in descending order by the Z value of the sprite, and the screen is output in the order of the sorted sprites.

With this configuration, a sprite having a large Z coordinate value is output first, and a sprite having a small Z coordinate value is output later. If there is a sprite having the same X and Y coordinate values, a sprite having a small Z value is overwritten on a previously displayed sprite because it is written out later. That is, the smaller the Z value, the higher the priority (priority).
Is displayed on the screen as shown in FIG.

As can be seen from the comparison with FIG. 2, the only difference in the expression is that the sense of incongruity disappears and the image becomes a natural image with a sense of perspective.

Next, the display between the sprite and the background will be described. The background is usually stationary because it is the background. At least it does not move randomly according to the player's operation or program logic like a sprite.

However, this simplifies the movement of the sprite and makes the game monotonous. In order to complicate a game or to construct a powerful screen with a three-dimensional effect, there is a case where an expression method is needed in which sprites are freely sewn between backgrounds to move.

FIG. 6 shows a BAT record structure. It has no information about the coordinates. In the background display, the screen is displayed according to the order of the records written in the BAT.
This is because there is no need to refer to coordinate values.

In this example, a sprite has a size of 16 × 16 dots as one unit, and a background has a size of 8 × 8 dots of a character as one unit. In the background, these characters are stacked to form one background.

FIG. 7 compares the size of the sprite and the size of the character. The size of the character is one-fourth the size of the sprite.

Normally, a sprite is displayed above a character. However, in some cases, the opposite is true. For this purpose, an SPBG item as shown in FIG. 4 is provided in the sprite record, and by setting this to 0, the background can be preferentially displayed.
When SPBG = 1, sprite priority display is performed.

By using this, it is possible to express either behind or before the background. However, this method cannot be used to represent a person who has halved his body between screens as in the example of FIG. 8 (assuming a screen is a character display and a person is a sprite display).

Therefore, in the present invention, a method is used in which a sprite having the same shape as the screen is prepared for the part of the screen where the person is shadowed, the person is displayed with SPBG = 1, and this sprite is overwritten on the person. I take the. In this way, it looks as if the person is half hidden in a screen.

Of course, before executing such a method, it is necessary to check the positional relationship between the screen and the person, so that the coordinates of the screen must also be stored in the program. In FIG. 8, Z1, Z2, and Z3 represent depth. This is done in exactly the same way as for sprites versus sprites.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS For the purpose of expressing the depth of the present invention, it has been described that main display objects such as sprites and backgrounds are managed by three-dimensional coordinates. An example of managing and expressing two-dimensionally will be described.

FIG. 9 is a view as seen from obliquely above the sky. Since a person moves only on a two-dimensional plane, the Z in the height direction
The axes do not affect the game at all, so there is no need to consider them directly. Therefore, FIG. 9 is displayed on the screen in a planar manner as shown in FIG.

Even if the persons A, B, and C are displayed in the same shape and the same size, the sense of perspective is slightly lost, but there is not much discomfort in the frame where the range of action is limited. Trees and houses are also displayed in the same shape and the same size.

In this case, the number of patterns to be registered in SG and CG can be reduced. People are displayed as sprites and others are displayed as characters.

By the way, when the images are displayed in this manner, the positional relationship between them can be clearly distinguished only by the picture in FIG. However, as you move the person, the place where the person overlaps appears. For example, if person A approaches person B and part of the body is B
If the display as shown in FIG. 2 is performed when the images overlap, the sense of perspective is lost and the picture becomes uncomfortable.

Therefore, using the coordinate management and display method of the present invention, the sprites are sorted in descending order by distance coordinates Y representing the depth from the reference point, and the sprites are displayed in the sorted order. FIG.
Is a case of the state of FIG. 10, where the coordinates are C,
B, D, and A are arranged in this order.

If the sprites are displayed in this order, even if they overlap, the sprite displayed later overwrites the previous sprite, so that the display does not lose the depth.

Consider the background and sprites. Since trees and buildings in the background are characters, there is no need for coordinates when displayed on the screen. However, in order to know the positional relationship with the sprite, coordinates are given. In addition, the size information is also stored at the same time. By doing so, the positional relationship between the person and the tree or building becomes clear.

Let's consider the case where a person goes off the road and hides behind a tree. If the person is completely behind the tree,
The sprite display may be performed by setting the SPBG of the person to 0.

However, when only a part is shaded, this method cannot be used. Therefore, a sprite having the same shape as the background tree is registered in advance, and after displaying the target person, the sprite is overwritten on the target tree.

Although it is permissible to convert only the part of the tree where the sprite is shaded into sprites, the program is simpler if the whole tree is represented by sprites (however, a plurality of sprites may be connected).

FIG. 1 is a flowchart showing the above display procedure.
2. Most games can express the depth (Y coordinate) by the two-dimensional coordinate management described here.

[0037]

By introducing the concept of the present invention, the depth can be clearly expressed, and not only sprite-to-sprite,
Depth of sprite versus background is also possible. This has the effect that a more complex and more sophisticated game can be designed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a VRAM of a computer game device.

FIG. 2 is an example of a picture in which the perspective (rear-to-back relationship) is ambiguous.

FIG. 3 is a diagram showing a positional relationship in three-dimensional coordinates.

FIG. 4 is a record configuration of an SAT.

FIG. 5 is an example of a picture having a perspective (a front-back relationship).

FIG. 6 is a diagram showing a record configuration of a BAT.

FIG. 7 is a diagram showing the size of a character and a sprite.

FIG. 8 is a diagram showing a screen and a person sandwiched between the screens.

FIG. 9 is a view seen from above.

FIG. 10 is a diagram when the scenery of FIG. 9 is displayed for a game;

FIG. 11 is an example of a case where human coordinates are sorted by Y coordinates.

FIG. 12 is a display procedure of a sprite and a character according to the present invention.

Claims (3)

(57) [Claims] 1. A screen in which a background (background) formed by arranging a set of dots of a specific size and a sprite (foreground) are superimposed on two types of screens. When a part of a sprite is hidden in the background in the image display of a computer game device that displays a superimposed screen by including information that preferentially displays the ground, the same sprite as the background image of the hidden part is created And displaying the sprite in preference to the sprite to be hidden. 2. A screen in which two types of screens called a background (background) and a sprite (foreground) formed by arranging a set of dots of a specific size are overlapped, and a sprite or a back In a computer game device that displays a superimposed screen by including information that preferentially displays the ground, if a part of the sprite is hidden in the background, create the same sprite as the background image of the hidden part, A computer game apparatus comprising: means for displaying a sprite in preference to a hidden sprite. 3. A screen in which two types of screens called a sprite (foreground) and a background (background) formed by arranging a dot set of a specific size are superimposed on each other. In the image display of a computer game that displays a superimposed screen by including information that preferentially displays the ground, if a part of the sprite is hidden in the background, create the same sprite as the background image of the hidden part And a recording medium for a computer in which a program for displaying a sprite in preference to a hidden sprite is recorded.